loop6: detected capacity change from 0 to 32768 ================================================================== BUG: KASAN: slab-use-after-free in dtCompare fs/jfs/jfs_dtree.c:3345 [inline] BUG: KASAN: slab-use-after-free in dtSearch+0x1683/0x21b0 fs/jfs/jfs_dtree.c:650 Read of size 1 at addr ffff888055beab90 by task syz.6.2589/13168 CPU: 0 UID: 0 PID: 13168 Comm: syz.6.2589 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 dtCompare fs/jfs/jfs_dtree.c:3345 [inline] dtSearch+0x1683/0x21b0 fs/jfs/jfs_dtree.c:650 jfs_lookup+0x155/0x380 fs/jfs/namei.c:1461 __lookup_slow+0x297/0x3d0 fs/namei.c:1855 lookup_slow+0x53/0x70 fs/namei.c:1872 walk_component+0x2d2/0x400 fs/namei.c:2190 lookup_last fs/namei.c:2691 [inline] path_lookupat+0x163/0x430 fs/namei.c:2715 filename_lookup+0x212/0x570 fs/namei.c:2744 user_path_at+0x3a/0x60 fs/namei.c:3536 __do_sys_chdir fs/open.c:558 [inline] __se_sys_chdir+0x91/0x280 fs/open.c:552 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdd5c78f6c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fdd5d62e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 00007fdd5c9e5fa0 RCX: 00007fdd5c78f6c9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fdd5c811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdd5c9e6038 R14: 00007fdd5c9e5fa0 R15: 00007ffd46fe3e28 Allocated by task 12695: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4948 [inline] slab_alloc_node mm/slub.c:5258 [inline] kmem_cache_alloc_lru_noprof+0x36c/0x6e0 mm/slub.c:5277 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105 alloc_inode+0x6a/0x1b0 fs/inode.c:346 new_inode+0x22/0x170 fs/inode.c:1175 jfs_fill_super+0x569/0xd80 fs/jfs/super.c:511 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1699 vfs_get_tree+0x92/0x2b0 fs/super.c:1759 fc_mount fs/namespace.c:1209 [inline] do_new_mount_fc fs/namespace.c:3652 [inline] do_new_mount+0x302/0xa10 fs/namespace.c:3728 do_mount fs/namespace.c:4051 [inline] __do_sys_mount fs/namespace.c:4240 [inline] __se_sys_mount+0x313/0x410 fs/namespace.c:4217 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12: kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kmem_cache_free+0x197/0x640 mm/slub.c:6774 rcu_do_batch kernel/rcu/tree.c:2605 [inline] rcu_core+0xcab/0x1770 kernel/rcu/tree.c:2861 handle_softirqs+0x27d/0x880 kernel/softirq.c:626 do_softirq+0xec/0x180 kernel/softirq.c:523 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:835 [inline] nsim_dev_trap_report_work+0x7c7/0xb80 drivers/net/netdevsim/dev.c:866 process_one_work+0x93a/0x15e0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 destroy_inode fs/inode.c:401 [inline] evict+0x931/0xae0 fs/inode.c:861 jfs_put_super+0x148/0x190 fs/jfs/super.c:201 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 kill_block_super+0x44/0x90 fs/super.c:1730 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1328 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e9/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888055bea4a0 which belongs to the cache jfs_ip of size 2216 The buggy address is located 1776 bytes inside of freed 2216-byte region [ffff888055bea4a0, ffff888055bead48) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x55be8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888033dfe301 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff888143e853c0 dead000000000122 0000000000000000 raw: 0000000000000000 00000000800d000d 00000000f5000000 ffff888033dfe301 head: 00fff00000000040 ffff888143e853c0 dead000000000122 0000000000000000 head: 0000000000000000 00000000800d000d 00000000f5000000 ffff888033dfe301 head: 00fff00000000003 ffffea000156fa01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_RECLAIMABLE|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 9251, tgid 9250 (syz.5.1146), ts 208666721361, free_ts 22224820342 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3b0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xf56/0x1990 mm/slub.c:4651 __slab_alloc+0x65/0x100 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5246 [inline] kmem_cache_alloc_lru_noprof+0x3fe/0x6e0 mm/slub.c:5277 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105 alloc_inode+0x6a/0x1b0 fs/inode.c:346 iget_locked+0x135/0x6c0 fs/inode.c:1473 jfs_iget+0x24/0x470 fs/jfs/inode.c:29 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469 __lookup_slow+0x297/0x3d0 fs/namei.c:1855 lookup_slow+0x53/0x70 fs/namei.c:1872 walk_component+0x2d2/0x400 fs/namei.c:2190 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 __free_pages mm/page_alloc.c:5329 [inline] free_contig_range+0x1bd/0x4a0 mm/page_alloc.c:7172 destroy_args+0x69/0x660 mm/debug_vm_pgtable.c:983 debug_vm_pgtable+0x38f/0x3a0 mm/debug_vm_pgtable.c:1372 do_one_initcall+0x1fb/0x870 init/main.c:1378 do_initcall_level+0x104/0x190 init/main.c:1440 do_initcalls+0x59/0xa0 init/main.c:1456 kernel_init_freeable+0x334/0x4b0 init/main.c:1688 kernel_init+0x1d/0x1d0 init/main.c:1578 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Memory state around the buggy address: ffff888055beaa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055beab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888055beab80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888055beac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888055beac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================